关于mybatis框架遇到的问题！(语言-java)

Question

SqlMapConfig

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>


    <properties resource="jdbc.properties"></properties>


    <environments default="developemnt">
      
        <environment id="developemnt">
      
            <transactionManager type="JDBC"></transactionManager>
   
        
                <property name="driver" value="${driverClassName}"></property>
                <property name="url" value="${url}"></property>
                <property name="username" value="${username}"></property>
                <property name="password" value="${password}"></property>
            </dataSource>
        </environment>
    </environments>

    <mappers>
        <mapper resource="StudentMapper.xml"></mapper>
    </mappers>
</configuration>

Mapper

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="rar">

    <select id="getAll" resultType="Student">
        select sno,name from students
    </select>
</mapper>

jdbc.properties文件

driverClassName=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://localhost:3306/friend?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=false
username=root
password=123456

测试类

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.*;
import org.junit.Test;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.util.List;

public class MyTest {
    @Test
    public void testA() throws IOException {
        //使用文件流读取核心配置文件
        InputStream in = Resources.getResourceAsStream("SqlMapConfig.xml");
        //创建SqlSessionFactory工厂
        SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(in);

        //取出sqlSession
        SqlSession sqlSession = factory.openSession();
        //取出查询操作
        List<Student> list = sqlSession.selectList("rar.getAll");
        list.forEach(student -> System.out.println(student));
        //关闭sqlSession
        sqlSession.close();
    }
}

表

结果

原因是啥吗

Answer 1

一点毛病没有，你把Student类的toString方法重写一下；直接用idea的右键一键生成就可以了。